Available library capacity

摘要

A data storage library is described including a plurality of tape cartridges each of which substantially houses a tape medium with a known storage capacity that includes both available storage space for storing new user data and consumed storage space which contains previously stored user data. Each tape cartridge also possesses an associated auxiliary memory device adapted to acquire and maintain knowledge of the available storage space relative to the associated tape cartridge. The library further includes at least one tape drive capable of writing the new user data and reading the previously stored user data from the tape medium. The tape drive can transfer the knowledge of the available storage space remaining on each of the tape cartridges to the auxiliary memory device associated with each of the tape cartridges which can then be transferred a user of data immediately or at a later time.